Mass storage capabilities are critical to biomedical visualization. Rendered data constitute huge files that must be saved to mass storage; this is especially true for virtual reality. CTC is the first center to successfully implement the High Performance Storage Systems (HPSS) technoogy in an IBM RS/6000 POWERParallel SP environment. HPSS is a new-generation, hierarchical, mass storage system software that was designed and built to provide scalability and performance. Anticipated use of the system will have it managing millions of files and petabytes of data. HPSS relies heavily on parallel I/O to attain impressive aggregate data rates. CTC will be an early deployment of the complete system, wich is a cooperative development project originated by IBM Government Systems and four Department of Energy Laboratories.